Posted by Ann NY on May 15, 2001, at 7:31:50
In reply to Re: Xanax v. generic Xanax, posted by BrittPark on May 2, 2001, at 20:14:15
I'm not a pharmacologist but: Since the 1980's there have been huge advances in understanding manufacturing influences on formulation properties, especially subtle effects on the drugs crystal structure "polymorphism". Now that the problem is known it is now checked to ensure the formulations of brand and generics dissolve in the same manner. Or, the genetic must dissolve in accordance to the original Xanax formulation. Xanax is a trademark, so it can still be used even if the formulation (not drug) has changed. (i.e. Effexor can be used to name both immediate release formulations and extended release formulations)
If a clinical difference is noticed, it should only be dosage related.
Your different experiences on Xanax compared to generic may be psychologically influenced (but real) or Xanax may have slightly improved the formulation since originally approved. These little changes go through the FDA rather quickly.
Also, the amount of water you take with the med can greatly influence the bioavilability of certain drugs. I don't know if Xanax falls into this category.
So is there a slight difference, maybe. Spend the $5 and put your mind at ease.
> > I take 1 mg generic Xanax [Greenstone Labs] and it didn't work that well the last couple of times I took it[at night for insomnia]. My brother swears the generic does not work as well as the actual name brand Xanax. I thought it might depend on the lab that makes it. Is my brother right? If I want to try Trazodone, I've read it's not "even" all the time, and my friend takes the brand name Deyserel. Anybody in the know have an opinion? Should I ask for the Xanax brand? With insurance, it's just $5 more for 3 month supply. Thanks.
> > Joy
> > Joy
>
> Unfortunately generic equivalents are not always
> equivalent. Certain generic imipramines have 30%
> lower bioavailability than the name brand tofranil.
> (Source late 1980s Psyhopharmacology text book).
> Certain generic clonazepams have 50% less
> bioavailability than the name brand klonopin.
> (Source my psychiatrist). If money is no object
> get the brand name for any drug. That way you'll
> have a repeatable baseline for drug titrations
> etc. If money is an issue, ask your pharmacist
> about the generics they use. The FDA has a classification
> scheme for bioequivalence, and your pharmacist
> should be able to tell you the class their generic
> falls into.
poster:Ann NY
thread:61013
URL: http://www.dr-bob.org/babble/20010515/msgs/63052.html